A customer would like to be able to reset a replicaset member's local DB while the server remains online. Specifically, assuming the server started in replSet1, would would like to:
a) clean replica set configuration, and be able to add this instance to different existing replica set with name replSet2.
b) clean replica set configuration and be able to create new Replica Set starting from this instance (keeping all data in).

Because we use mongod embedded in another product, it is not possible for us to make these changes offline.